1. Field of the Invention
The invention relates to a hearing aid for improving the hearing ability of the hard of hearing, comprising an array of microphones, the electrical output signals of which are fed to at least one transmission path belonging to an ear.
2. Description of the Related Art
A device of this type is known from the article entitled “Development of a directional hearing instrument based on array technology” published in the “Journal of the Acoustical Society of America”, Vol. 94, Edition 2, Pt. 1, pages 785–798, August 1993.
It is generally known that loss of hearing in people can be compensated for by means of a hearing aid, in which amplification of the received sound is used. In environments with background noise, for example when several people are speaking at once, as is the case at a cocktail party, the hearing aid amplifies both the desired speech and the noise, as a result of which the ability to hear is not improved.
In the abovementioned article the authors describe an improvement proposal. The hearing aid disclosed in the article consists of an array of, for example, five directional microphones, as a result of which it is possible for the person who is hard of hearing to understand someone who is speaking directly opposite him or her. The background noise which emanates from other directions is suppressed by the array.
From U.S. Pat. No. 4,956,867 an apparatus for suppressing signals from noise sources surrounding a target source is known. This apparatus comprises a receiving array including two microphones spaced apart by a distance. The outputs of the microphones are combined such that a primary signal channel and a noise signal channel are obtained. The outputs of the channels are substrated for cancelling the noise from the primary signal channel.